Analysis of Minute Objects Using the SurveyIR Sample Compartment Type Infrared Microscopy System

Significance of the Topic

Analysis of minute samples by Fourier transform infrared (FTIR) microspectroscopy is essential in fields such as materials science, environmental monitoring, quality control and forensic analysis. The ability to identify chemical composition and structural information of objects down to tens of micrometers enables precise contamination assessment, polymer and fiber characterization, and rapid decision making in research and industrial laboratories.

Objectives and Study Overview

This application note demonstrates the integration of a compact FTIR spectrophotometer (IRSpirit™-X) with a sample compartment type infrared microscopy system (SurveyIR). The aim is to evaluate performance in measuring and identifying very small objects (≈60–600 µm) using transmission and ATR sampling modes, and to illustrate workflow from sample mounting to spectral library searching.

Methodology and Measurement Conditions

Measurements were performed on an IRSpirit-TX model equipped with a DLATGS detector, using the SurveyIR microspectroscopy accessory. Key parameters:

• Resolution: 8 cm⁻¹
• Number of scans: 128
• Apodization: SqrTriangle
• Aperture sizes: φ60, φ100, φ160, φ200, φ250, φ2000 µm

Transmission measurements employed diamond compression cells, while single-reflection ATR used diamond and germanium crystals. Manual X–Y sample centering and Z-axis focusing allowed precise alignment of micro-objects.

Used Instrumentation

• Shimadzu IRSpirit-X FTIR spectrophotometer (TX model with DLATGS detector)
• SurveyIR sample compartment infrared microscopy system
• Diamond compression cell and KBr pellet holder
• Diamond and Ge single-reflection ATR accessories

Main Results and Discussion

Colorless micro-objects (~200 × 100 µm) compressed on a diamond cell were successfully analyzed in transmission mode, yielding spectra matched to sucrose and vegetable oil in the standard library. Fibrous contaminants (~100 µm width) were identified using both standard and custom Shimadzu Contaminant Library entries; polyester and cotton were distinguished, and mixed polyester-cellulose fibers were resolved. Thick, transparent samples (~600 × 400 µm) were analyzed via diamond ATR with a 2 mm aperture, avoiding sample thinning; spectra indicated acrylic adhesive components. The use of the Contaminant Library improved match accuracy for real-world mixtures and composite materials.

Benefits and Practical Applications

• Compact footprint allows installation in constrained laboratory spaces
• Standard FTIR detector enables measurement without liquid nitrogen cooling
• Flexible sample handling for transmission, reflectance and ATR modes
• Accurate micro-object centering and high-resolution imaging for sample positioning
• Enhanced spectral identification using custom contaminant libraries

Future Trends and Potential Applications

Ongoing developments may include automated stage control for high-throughput microanalysis, integration of advanced AI-driven spectral interpretation tools, expansion of micro-sample libraries for complex mixtures, and coupling with microfluidic platforms for in situ reaction monitoring. Emerging detector technologies and improved sampling accessories promise to extend sensitivity to sub-micrometer scales and broaden applicability to live cell and polymer dynamics studies.

Conclusion

The combination of IRSpirit-X and SurveyIR provides a versatile, sensitive solution for FTIR analysis of minute objects. Its compact design, flexible sampling options and enhanced library search capabilities make it a powerful tool for diverse applications in research, QA/QC and contamination analysis. Consistent performance across transmission and ATR modes enables rapid identification of small particles, fibers and adhesives, supporting informed decision-making in laboratory workflows.